50mm Sandwich Panel: Specs, Spans and When It’s Enough

Shandong Fuqiang Technical & Application Team | Corporate Technical / Product Application Team | Published: 27 August 2026

At 50 mm, Fuqiang produces the double-sided steel PU wall panel at 1000 mm cover width, 0.3–0.8 mm facings and 0.019–0.023 W/(m·K), plus rock wool and PU edge-sealed rock wool panels at the same thickness. The core, not the millimetre figure, decides whether 50 mm is enough.

“50 mm panel” is not a product

It is a thickness that five different Fuqiang product lines happen to share. A quotation for a 50 mm panel can describe a rigid PU wall panel, a mineral wool wall panel, a PU edge-sealed rock wool wall panel, or either of two roof profiles. They differ in conductivity by a factor of more than two, in weight, in fire behaviour and in what the joint does.

Product line at 50 mm	Cover width	Facing steel	Thermal conductivity
양면 강판 PU 샌드위치 패널	1000 mm	0.3–0.8 mm	0.019–0.023 W/(m·K)
PU 가장자리 밀봉 암면 샌드위치 벽 패널	1000 mm
내화성 암면 단열 벽체 패널	950 mm		approx. 0.043 W/(m·K)
PU 가장자리 실링 암면 골판형 지붕 패널	1000 mm coverage	0.4–0.8 mm	0.035–0.041 W/(m·K)
히든 패스너 PU 3파 골판 지붕 패널	1000 mm coverage	0.4–0.8 mm	≤ 0.023 W/(m·K)

Note the 950 mm entry. Swapping the rock wool wall panel in at the same thickness changes the module, and on a 60 m elevation that is roughly three extra panels and a different closing detail. Compared with single-product supplier listings that present one core at 50 mm and leave the reader to assume the rest transfers, the module is the first thing that does not.

Full published specification: Double-Sided Steel PU Sandwich Panel

Parameter	Published value
Effective width	1000 mm
Thickness range	50–200 mm
Facing steel thickness	0.3–0.8 mm, both faces
Core	Rigid polyurethane, density approx. 42 kg/m³
Thermal conductivity	0.019–0.023 W/(m·K)
Water absorption	≤ 5%
Joint system	Hidden-screw tongue and groove
Fire classification	Not stated on this product page
Span / load table	Not published

Two blanks matter for a distribution facility. The PU wall panel page carries no fire classification statement, so nothing about a Euroclass or a GB 8624 grade should be assumed for it from the roof panel pages, which do reference GB 8624 Grade B1 without publishing the report number or laboratory. And there is no published span table, which the next section deals with directly.

The hidden-screw tongue and groove is worth reading as a specification, not a feature. No fastener head sits on the external face, which removes the most common water path and the most common thermal bridge on a screw-fixed elevation. It also means the panel installs in one direction only, and a mis-sequenced run has to come off rather than be closed from the other end.

The span question, answered honestly

There is no published span table for these panels, and any span figure quoted for a 50 mm sandwich panel without a load case attached is not usable in a tender.

Span capacity for a self-supporting double-skin metal-faced panel is not a property of thickness. It is the output of a calculation combining:

• Wind pressure and suction for the site, including local corner and edge zones
• Facing steel thickness and yield strength, which for this panel range across 0.3–0.8 mm
• Whether the panel is single-span or continuous over two or more supports
• Deflection limit set by the project, not by the manufacturer
• Core shear and the bond between core and facing
• For roof profiles, imposed and snow load plus point loads from maintenance access

EN 14509 is the product standard covering factory-made self-supporting double-skin metal-faced insulating panels for roofs, external walls, internal walls, partitions and ceilings, and it is where the structural verification for these assemblies sits. BSI lists BS EN 14509:2013 as current and under review, so check the applicable edition for the jurisdiction at tender stage.

What that means in practice for a warehouse developer: at 0.3 mm facings, a 50 mm panel is an internal partition or a low-exposure cladding element. At 0.6–0.8 mm facings on the same 50 mm core, the same nominal panel behaves very differently. Specify the facing thickness and the purlin or girt spacing together, and get the load calculation for that pair in writing before releasing the steel frame drawing.

PU or rock wool, at the same 50 mm

	50 mm PU wall panel	50 mm rock wool wall panel	50 mm PU edge-sealed rock wool
Cover width	1000 mm	950 mm	1000 mm
Conductivity	0.019–0.023 W/(m·K)	approx. 0.043 W/(m·K)	Not published
Relative thermal performance	Roughly twice as insulating per mm	Baseline	Between the two, configuration-dependent
Fire statement published	None on the product page	Described as A-grade non-combustible, verification required per configuration	Class A stated, no certificate number published
Sound insulation published	Not stated	≥ 30 dB	Not stated
Edge condition	PU core to the joint	Exposed mineral wool at cut edge	PU sealing around the wool edge
Coating options published	Confirm per order	Confirm per order	PVDF, SMP, HDP, PE
Weight	Lighter	Heavier	Heavier

Neither column wins. A 50 mm PU panel gives the thermal performance of roughly 100 mm of rock wool, which is why it dominates ambient warehouse cladding. It does not give a fire classification, and on the PU wall panel page none is claimed.

Where a project has a fire-separation requirement — a boundary wall, a compartment line between storage bays, a wall adjoining an office or plant room — the thermal comparison stops being the relevant one. Rock wool answers that requirement and costs thickness and weight to do it. The edge-sealed variant exists because the exposed cut edge is where mineral wool takes on water and mechanical damage during handling, and sealing the perimeter in PU changes what sits at the panel edge, which is precisely the region a fire test evaluates. Ask for the report covering the configuration you are buying.

Where 50 mm is enough, and where it is not

50 mm is usually sufficient for:

1. Unconditioned distribution sheds and cross-dock buildings where the envelope moderates temperature rather than holding a setpoint
2. Internal partitions between warehouse bays with no fire-separation duty
3. Office fit-out partitions inside a larger shell
4. Canopies, plant enclosures and ancillary structures
5. Buildings in mild climates where the wall U-value is not the governing compliance item

Move to 75 or 100 mm when:

1. The building is temperature-controlled, even loosely. Once a setpoint exists, running cost compounds over a twenty-year hold and the thickness step is a rounding error against it
2. A U-value target governs and the calculation fails at 50 mm. Run it before choosing, not after
3. Acoustic separation is required against a boundary or an office
4. Wind loading pushes required facing thickness to the top of the 0.3–0.8 mm range, at which point a thicker core is often the cheaper route to the same structural outcome than heavier steel on both faces
5. Fire separation applies and the answer is 75 or 100 mm rock wool, which is where the PU edge-sealed rock wool panel’s commonly supplied thicknesses sit

The 0.043 versus 0.021 comparison is the one most often misread. Halving the conductivity does not mean the wall performs twice as well, because the assembly U-value under ISO 6946 includes both steel facings, the joint repeating every metre and every fastener through the build-up. Two panels with the same core thickness and different joint details can land in different compliance brackets.

Turning this into a purchase specification

1. Fix the U-value target from the building’s use, then calculate the assembly per ISO 6946 including joints and fixings. Thickness falls out of that, and the conductivity figures used should come from a stated test method such as ASTM C518.
2. Confirm the fire requirement with the authority having jurisdiction before comparing cores. That single answer decides PU versus rock wool more often than thermal performance does.
3. Specify facing steel thickness explicitly. “50 mm panel” without it is not a specification.
4. Get the load calculation for your facing thickness and support spacing, and align it with the frame drawing.
5. Fix the cover width in the take-off. 1000 mm and 950 mm produce different panel counts and different closure details on the same elevation.
6. Quantify trims, corners, flashings, closures and joint covers on the same drawing. They are fabricated to order in galvanized, Al-Zn coated, stainless or aluminium substrate with PE, PVDF or powder coating, and leaving them until after panel release is what holds up site.
7. Check the programme against published guidance of roughly 7–15 working days for standard orders and 15–25 for customised orders, which moves with configuration and quantity.

Cost

Fuqiang quotes on a project basis with no published price per square metre, determined by specification, quantity, customisation, surface material and coating, packaging and shipping terms, with a formal quotation prepared once technical requirements are confirmed. Any per-square-metre figure circulating for a “50 mm panel” without a defined facing thickness, coating and core is describing a different product from the one that will arrive.

Trade terms include EXW, FOB, CFR, CIF and DDP, with FCL, LCL and door-to-door logistics. For a large shed, the freight comparison between a 50 mm PU panel and a 50 mm rock wool panel is not marginal, and a landed-cost model built on area alone will understate the mineral wool option.

Questions buyers often ask

What is a 50 mm sandwich panel used for?

Most commonly ambient warehouse and factory cladding, internal partitions, office fit-outs within a larger shell, and ancillary structures. It is the entry thickness across Fuqiang’s wall and roof lines rather than a specific product.

What is the U-value of a 50 mm sandwich panel?

It depends on the core and the assembly. A PU core at 0.019–0.023 W/(m·K) and a rock wool core at approximately 0.043 W/(m·K) produce very different results at the same thickness, and the assembly U-value must be calculated per ISO 6946 including facings, joints and fasteners.

How far can a 50 mm panel span?

No span table is published, and no honest figure exists without a load case. Span depends on wind load, facing steel thickness across the 0.3–0.8 mm range, single or continuous span, and the project’s deflection limit. Request the calculation for your configuration.

Is 50 mm enough for a cold store?

For a temperature-controlled facility the U-value calculation almost always drives thickness above 50 mm. Treat it as a calculation rather than a starting assumption.

Is a 50 mm PU panel fire rated?

Fuqiang’s double-sided steel PU sandwich panel page states no fire classification. Where a fire requirement applies, the rock wool and PU edge-sealed rock wool lines are the relevant products, and the test report covering your configuration should be requested rather than assumed.

Can I mix 50 mm walls with a thicker roof?

Yes, and it is common. Roof and wall requirements rarely coincide, and the roof profiles are available from 50 to 150 mm core independently of the wall selection.

자주 묻는 질문

What is a 50 mm sandwich panel used for?

Most commonly ambient warehouse and factory cladding, internal partitions, office fit-outs within a larger shell, and ancillary structures. It is the entry thickness across Fuqiang's wall and roof lines rather than a specific product.

What is the U-value of a 50 mm sandwich panel?

It depends on the core and the assembly. A PU core at 0.019–0.023 W/(m·K) and a rock wool core at approximately 0.043 W/(m·K) produce very different results at the same thickness, and the assembly U-value must be calculated per ISO 6946 including facings, joints and fasteners.

How far can a 50 mm panel span?

No span table is published, and no honest figure exists without a load case. Span depends on wind load, facing steel thickness across the 0.3–0.8 mm range, single or continuous span, and the project's deflection limit. Request the calculation for your configuration.

Is 50 mm enough for a cold store?

For a temperature-controlled facility the U-value calculation almost always drives thickness above 50 mm. Treat it as a calculation rather than a starting assumption.

Is a 50 mm PU panel fire rated?

Fuqiang's double-sided steel PU sandwich panel page states no fire classification. Where a fire requirement applies, the rock wool and PU edge-sealed rock wool lines are the relevant products, and the test report covering your configuration should be requested rather than assumed.

Can I mix 50 mm walls with a thicker roof?

Yes, and it is common. Roof and wall requirements rarely coincide, and the roof profiles are available from 50 to 150 mm core independently of the wall selection.